From dc7637c402b90a197d3f21a3d78f2b00b67ea22a Mon Sep 17 00:00:00 2001 From: Nathan Lynch Date: Tue, 12 Dec 2023 11:01:54 -0600 Subject: powerpc/rtas: Serialize firmware activation sequences Use rtas_ibm_activate_firmware_lock to prevent interleaving call sequences of the ibm,activate-firmware RTAS function, which typically requires multiple calls to complete the update. While the spec does not specifically prohibit interleaved sequences, there's almost certainly no advantage to allowing them. Reviewed-by: "Aneesh Kumar K.V (IBM)" Signed-off-by: Nathan Lynch Signed-off-by: Michael Ellerman Link: https://msgid.link/20231212-papr-sys_rtas-vs-lockdown-v6-7-e9eafd0c8c6c@linux.ibm.com --- arch/powerpc/kernel/rtas.c | 4 ++++ 1 file changed, 4 insertions(+) (limited to 'arch/powerpc/kernel') diff --git a/arch/powerpc/kernel/rtas.c b/arch/powerpc/kernel/rtas.c index 4d28983e8b1d..72f6b5a402dd 100644 --- a/arch/powerpc/kernel/rtas.c +++ b/arch/powerpc/kernel/rtas.c @@ -1734,10 +1734,14 @@ void rtas_activate_firmware(void) return; } + mutex_lock(&rtas_ibm_activate_firmware_lock); + do { fwrc = rtas_call(token, 0, 1, NULL); } while (rtas_busy_delay(fwrc)); + mutex_unlock(&rtas_ibm_activate_firmware_lock); + if (fwrc) pr_err("ibm,activate-firmware failed (%i)\n", fwrc); } -- cgit v1.2.3